Recently, positive photoresists have been widely used for forming electronic circuit patterns, and in most of the positive photoresists a composition containing a novolak resin and a naphthoquinone diazide compound as a photosensitive agent is used. In the composition, the novolak resin can be dissolved in an aqueous alkaline solution without swelling. The naphthoquinone diazide compound acts to reduce the alkali solubility of the novolak resin, while the compound is decomposed by irradiation of ultraviolet ray, etc. and converted into indene carboxylic acid to increase the alkali solubility of the novolak resin, and thus the composition is useful as the positive photoresist. However, this composition is poor in reactivity to a visible light, and disadvantageous in that sufficient resolution cannot be achieved in the case of forming a fine pattern.
Photosensitive compositions comprising a compound capable of generating an acid by light irradiation, a compound having a group derived from a polyfunctional vinyl ether compound, etc., are disclosed in JP-A-6-295064, JP-A-7-146552, JP-A-11-153858, and JP-A-11-174680. However, these compositions have disadvantages of poor yield, which is due to decrease of thermal crosslinking efficiency by diffusion limitation, and poor storage stability.
Also in the field of planography, in recent years there has been increasing interest in lithographic printing materials capable of directly plate-making using a visible laser or an infrared laser instead of conventional systems utilizing an ultraviolet light. JP-A-7-186562 and WO 02/11996 disclose photothermal type positive plate-making materials using an infrared laser. However, since these materials use a long wavelength laser as a light source, these materials are disadvantageous in view point of obtaining high resolution.
As a stable, high-energy laser, which is presently used in the above applications, those having an output wavelength within the visible region are often used, and examples thereof include an argon ion laser having oscillation lines at the wavelengths of 488 nm and 514.5 nm and a YAG laser having an emission line at 532 nm as the second high harmonic wave. Accordingly, there is a demand for a compound having a high sensitivity to these wavelengths.